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The purpose of this paper is to investigate the effect of an admixture, Swine-waste Bio-char (SB), on the water absorption characteristics of cement pastes.

The effect of SB percentages, heat treatment temperatures, water/binder ratios, and age on the water absorption percentages (WAPs) of SB modified cement pastes were investigated using scanning electron microscopy-energy dispersive spectra, FTIR, Brunauer-Emmett-Teller, and laboratory experiments.

The WAPs of cement pastes with SBs produced at the low treatment temperature (LTT) of 340°C and 400°C were significantly lower (p<0.01) than pastes with SBs produced at the high treatment temperature (HTT) of 600°C and 800°C. This was attributed primarily to the more dominant presence of hydrophobic alkyl surface groups from non-volatilized matter in LTT-SBs. This had also resulted in lower surface areas and pore volumes in LTT-SBs. As a result of the volatilization of these labile hydrophobic groups at HTT, HTT-SBs were more hydrophilic and had higher surface areas and pore volumes. Consequently, HTT-SB pastes had higher WAPs and no significant differences (p<0.05) existed between HTT-SB pastes and control pastes. Also, low water/binder ratios and aging reduced water absorption of SB modified cement pastes.

LTT-SBs reduce water absorption and could reduce concrete deterioration; and as such, associated building repair, maintenance, and adaptation costs. Notably, reductions in concrete water absorption will extend the service life of concrete buildings and infrastructures, particularly in unfavorable environmental conditions. The observed benefits are tempered by the current lack of information on the effects of SB on compression strength, workability, and other durability properties.

SB utilization in concrete buildings will enhance swine-waste disposal and reduce negative environmental impacts on swine farming communities; consequently, improving their quality of life.

Current bio-char research is focused on plant-derived bio-char toward soil remediation and contaminant removal, with very limited applications in concrete. This research advances knowledge for developing livestock-derived bio-char, as a PCRM, toward more sustainable and durable concrete structures.

The learning outcomes are as follows: successful students will demonstrate an understanding of challenges in producing and delivering a product in emerging economies; they will be able to analyze the tradeoffs in operational decisions of a social enterprise; and students will apply supply chain principles to solve social and environmental challenges.

Carbon Roots International is a social enterprise in Haiti producing and selling charcoal from sugar cane waste. Their operational challenge is designing a supply chain, which enables them to accomplish their social goals while building a profitable enterprise.

This case can be used in graduate operations management and supply chain management courses. The company in the case is a social enterprise.

Teaching Notes are available for educators only.

CSS 9: Operations and Logistics

The purpose of this study is to explore the feasibility of utilizing agricultural (almond shell, rice husk and wood) waste biochars for partial cement replacement by evaluating the relationships between the physiochemical properties of biochars and the early-age characteristics of cement pastes.

Biochars are prepared through the thermal decomposition of biomass in an inert atmosphere. Using varying percentages, biochars are used to replace ordinary Portland cement (OPC) in cement pastes at a water/binder ratio of 0.35. Characterization methods include XPS, FTIR, SEM, TGA, BET, Raman, loss-on-ignition, setting, compression and water absorption tests.

Accelerated setting in biochar-modified cement pastes is attributed to chemical interactions between surface functional groups of biochars and calcium cations from OPC, leading to the early development of metal carboxylate and alkyne salts, alongside the typical calcium-silicate-hydrate (C-S-H). Also, metal chlorides such as calcium chlorides in biochars contribute to the accelerate setting in pastes. Lower compression strength and higher water absorption result from weakened microstructure due to poor C-S-H development as the high carbon content in biochars reduces water available for optimum C-S-H hydration. Amorphous silica contributes to strength development in pastes through pozzolanic interactions. With its optimal physiochemical properties, rice-husk biochars are best suited for cement replacement.

While biochar parent material properties have an impact on biochar properties, these are not investigated in this study. Additional investigations will be conducted in the future.

Carbon/silicon ratio, oxygen/carbon ratio, alkali and alkaline metal content, chlorine content, carboxylic and alkyne surface functional groups and surface areas of biochars may be used to estimate biochar suitability for cement replacement. Biochars with chlorides and reactive functional groups such as C=C and COOH demonstrate potential for concrete accelerator applications. Such applications will speed up the construction of concrete structures and reduce overall construction time and related costs.

Reductions in OPC production and agricultural waste deterioration will slow down the progression of negative environmental and human health impacts. Also, agricultural, manufacturing and construction employment opportunities will improve the quality of life in agricultural communities.

Empirical findings advance research and practice toward optimum utilization of biomass in cement-based materials.

Purpose – The purpose of this research is to study the process conditions that give best yield and expected compositions of liquid smoke products that result during the pyrolisis process relying on predetermined variables.

Design/Methodology/Approach – Pyrolisis process running times are varied, that is, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, and 6 hourly. Condensing temperature maintained remained 25–30 °C. Products identification was applied by using gas chromotography mass spectroscopy.

Findings – Based on the research output, it was concluded that process conditions which give maximum yield were achieved when using double unit condenser (DUC) and time optional four hours, and it provides maximum volume liquid smoke product, and compositions of pyrolisis products. The process also created seven components, namely nepthalene, propanoic acid, 3,7 nanodiena, 2 metilguaiakol, 2-metoksi 4-methyl phenol, 4 ethyl-2 metoksil phenol, oxybanzene. Applying DUC during condensation phase may increase condensing force thereafter obtaining resulted products between 200% and 300% rather than using single unit condenser (SUC).

Research Limitations/Implications – This research was conducted on a fixed batch reactor made of a metal plate with a thickness of 3.0 mm. It carries 200 kg in capacity. In this phase, the moisture of candlenut shells might be kept in 10–12.5% wt. Process temperature applied ranged within 350–500 °C.

Originality/Value – In addition the study increased the theorical of understanding about pyrolisis process and Improving the production of liquid smoke from candlenut shell by pyrolisis process using the method of vapor condensation (Double unit condensor).

This paper aims to look at two recently published studies from the UK that report on using geo‐engineering solutions

The paper examines the geo‐engineering solutions suggested by the two publications: to remove CO₂ from the atmosphere, or reflect solar radiation back into space.

The paper finds that using geo‐engineering solutions to remove CO₂ from the atmosphere, or reflect solar radiation back into space, may well be needed in order help avoid dangerous temperature increases and climate change. The publications agree that certain solutions, ranging from artificial trees and algae covered buildings to fleets of sea salt spraying cloud ships are technically possible, could be effective and so need to be investigated further. However, both studies also emphasize that geo‐engineering is no silver bullet that can combat climate change in isolation. Moreover, it must not be seen as a diversion from efforts to reduce carbon emissions through mitigation. However, as reduction efforts to date have yet to deliver anything like what is needed, the studies state that geo‐engineering solutions of the type they propose should be further investigated, and those with merit invested in and used to buy the world time to decarbonize the global economy.

The two recently published studies from the UK provide useful information on geo‐engineering solutions to help avoid dangerous temperature increases and climate change.

This study aims to investigate the effect of reactor temperature on softwood and hardwood pyrolysis. Experiments are performed at six temperature levels ranging from 300 to 800°C under N₂ atmosphere. The weights of char, tar and gas yields produced were measured and recorded in percentage of initial weight of the pyrolyzed samples. Results of the study showed that hardwood produces maximum char, tar and gas yields of 41.02 per cent at 300°C,44.10 per cent at 300°C and 56.86 per cent at 800°C, respectively, whereas softwood produces maximum yields of 30.10 per cent at 300°C, 28.25 per cent at 300°C and 68.73 per cent at 800°C, respectively. Proximate analysis shows that volatile matter, fixed carbon, ash content and moisture content of hardwood are 74.83, 14.28, 2.81 and 8.08 per cent, respectively, and that of softwood are 79.76, 12.65, 0.98 and 6.61 per cent, respectively. Result of the elemental analysis results shows that the carbon, hydrogen, nitrogen, oxygen and sulphur contents for hardwood are 52.20, 6.45, 0.68, 39.64 and 1.03 per cent, respectively, and that of softwood are 45.95, 4.57, 0.56, 48.13 and 0.79 per cent, respectively. The higher heating value of hardwood and softwood are 21.76 and 16.50 kJ/g respectively. This study shows that char and tar yields decrease with increase pyrolysis temperature, whereas gas yield increases as pyrolysis temperature increases for the wood samples considered. At all temperatures considered in this study, gas yields are higher than tar and char yields for softwood, whereas for hardwood, tar yield decreases with increase in temperature with accompanying increase in gas yield.

Experiments are performed at six temperature levels ranging from 300 to 800°C under N₂ atmosphere.

At all temperatures considered in this study, gas yields are higher than tar and char yields for softwood, whereas for hardwood, tar yield decreases with increase in temperature with accompanying increase in gas yield.

Results of the study showed that hardwood produces maximum char, tar and gas yields of 41.02 per cent at 300°C,44.10 per cent at 300°C and 56.86 per cent at 800°C, respectively, whereas softwood produces maximum yields of 30.10 per cent at 300°C, 28.25 per cent at 300°C and 68.73 per cent at 800°C, respectively.

This study aims to evaluate the potential of using the in-nozzle impregnation approach to reuse recycled PET (RPET) to develop continuous banana fiber (CBF) reinforced bio-composites. The mechanical properties and fracture morphology behavior are evaluated to establish the relationships between layer spacing–microstructural characteristics–mechanical properties of CBF/RPET composite.

This study uses RPET filament developed from post-consumer PET bottles and CBF extracted from agricultural waste banana sap. RPET serves as the matrix material, while CBF acts as the reinforcement. The test specimens were fabricated using a customized fused deposition modeling 3D printer. In this process, customized 3D printer heads were used, which have a unique capability to extrude and deposit print fibers consisting of a CBF core coated with an RPET matrix. The tensile and flexural samples were 3D printed at varying layer spacing.

The Young’s modulus (E), yield strength (sy) and ultimate tensile strength of the CBF/RPET sample fabricated with 0.7 mm layer spacing are 1.9 times, 1.25 times and 1.8 times greater than neat RPET, respectively. Similarly, the flexural test results showed that the flexural strength of the CBF/RPET sample fabricated at 0.6 mm layer spacing was 47.52 ± 2.00 MPa, which was far greater than the flexural strength of the neat RPET sample (25.12 ± 1.94 MPa).

This study holds significant social implications highlighting the growing environmental sustainability and plastic waste recycling concerns. The use of recycled PET material to develop 3D-printed sustainable structures may reduce resource consumption and encourages responsible production practices.

The key innovation lies in the concept of in-nozzle impregnation approach, where RPET is reinforced with CBF to develop a sustainable composite structure. CBF reinforcement has made RPET a superior, sustainable, environmentally friendly material that can reduce the reliance on virgin plastic material for 3D printing.

The purpose of this paper is to explore the application of traditional Māori horticultural and ethnopedological practices in New Zealand whereby an inclusive “whole of landscape” approach known as “ki uta ki tai” – literally from “the source to the oceans” – is applied in a contemporary landscape.

A review of the traditional knowledge and practices around Māori horticulture and pedology was undertaken through interviews within Māori communities, including practitioners of this knowledge, and a literature review.

Traditional Māori practices contribute to a cultural management tool known as kaitiakitanga – literally the act of stewardship – which requires practitioners to contribute to the “landscape management” continuum based on a holistic approach reflecting the traditional and contemporary management needs. Examples of cultural praxis applied under these systems include the local knowledge aligned to soil origin, type and manageable characteristics and crop management praxis such as site selection, crop variety selection and rotation, or land and soil amendments.

Traditional Māori knowledge is primarily transmitted orally and retained within the community itself. Through colonisation this knowledge has been marginalised and is now retained by only a few experts across tribal regions. There is considerably more knowledge still held within communities, especially relative to the practical application of kaitiakitanga in the modern world.

Through political processes of the previous 170 years in New Zealand, Māori horticulturists are now restricted to pockets of lands in a discontinuous landscape over which they have a limited involvement. Urbanisation of the Māori community and ongoing marginalisation of traditional knowledge have further exasperated customary land and resource management approaches. Recent legislation includes reference to some traditional practices; however, there is limited statutory obligation on resource managers to practically apply them.

The specialist traditional knowledge aligned to horticulture and pedology has been relegated to only a few practitioners. None‐the‐less Māori continue to manage their crops with a wider, localised understanding of the landscape and of how decisions are likely to impinge on other sites within their traditional boundaries, drawn from the traditional knowledge of their forebears.